SeaFrance crossings from Dover to France are set to remain disrupted until at least midday as industrial action by ferry workers continues.
SeaFrance said talks were under way with staff
The pay dispute in France between SeaFrance officers and their union began on Thursday afternoon.
It led to traffic backlogs in Kent and the implementation by Kent Police of Operation Stack, where coastbound lorries are forced to queue on the M20.
The measure, between junctions 11 and 12, was lifted overnight.
SeaFrance said on Thursday that talks were under way with staff over pay.
A statement on the ferry operator's website informed passengers: "SeaFrance regrets to inform you that due to industrial action by onboard officers, crossings are currently suspended."
It advised passengers to call SeaFrance for information.
All other ferry services are operating as normal, but Kent Police advised people to check before setting out.